The present invention relates to the control and actuation of a firing sequence of a firearm. In particular, the present invention relates to a sensor system for monitoring and sensing application of a jarring event or acceleration and/or the movement of a firearm into an undesired orientation, and blocking the firing sequence of the firearm to prevent an inadvertent discharge of the firearm.
Inadvertent discharge of firearms is one of the leading causes of accidental injuries and deaths involving firearms. When a firearm is dropped or experiences the application of a force or other jarring event, the application of such force to the firearm can cause the firearm to inadvertently discharge either by causing the release of the firing pin in a percussion firing system in which the firing pin strikes and thus initiates firing of a round of ammunition within the chamber of a firearm, or, in the case of an electrically actuated firearm, causes an inadvertent trigger signal to be sent to the firearm control system in response to which an electric firing pulse is transmitted to the round of ammunition. In addition, there are times when a firearm is placed in an unsafe orientation or position and its trigger is inadvertently engaged, resulting in an inadvertent or undesired discharge of the firearm. For example, if the firearm is rotated upside down or canted at an angle of more than 45 degrees, such conditions generally are considered unsafe for the discharge of the firearm.
It is important, therefore, to be able to detect when a firearm is subjected to a jarring event and/or undesired movement, such as undue acceleration or being moved into an undesirable or unsafe orientation, and prevent the inadvertent or undesired discharge of the firearm, but without unduly interfering with the normal operation of the firearm and preventing its safe, authorized use.
Briefly described, the present invention relates to a sensor system for sensing firearm orientation and/or jarring events and preventing the firearm from being fired in an unsafe condition. The system includes one or more sensor arrays, having one or more sensors for sensing jarring events or acceleration and/or for determining the orientation of the firearm, mounted to a firearm at desired locations along or within the frame or stock of the firearm, and a control system to process the sensor signals and interrupt a firing sequence of the firearm when appropriate. The system detects acceleration from drops or other jarring events that can be distinguished from normal, safe handling of the firearm, which generally will only introduce a limited amount of acceleration that is significantly below the acceleration typically associated with accidental discharge from jar events. In addition, or alternatively, the system can have the capability of monitoring or sensing changes in firearm orientation(s) to orientations of a firearm that are undesirable or unsafe and that typically would not be used, such as, for example, the firearm being turned upside-down and when the angle or cant of the firearm with respect to one or more predetermined axes or orientation of the firearm passes some threshold value.
In one embodiment, the firing of a firearm will be prevented if excessive jarring or acceleration and/or improper orientation of the firearm are sensed. For purposes of this specification, the term xe2x80x9caccelerationxe2x80x9d should be construed as to include de-acceleration or negative acceleration as well as positive acceleration. In this embodiment, the firearm sensor system generally is omni-directional, so as to be capable of sensing a jarring event, or other application of force, in any direction, although it may be advantageous to have the sensor system have greater sensitivity in certain directions than others. The firearm sensor system will include one or more inertia switches or acceleration switches configured in a sensor array mounted on a mounting block attached to the firearm to create an omni-directional jar or acceleration sensor. The switches used generally are unidirectional so as to be affected by inertia in only one direction.
Typically, at least four to six unidirectional inertia or acceleration switches are mounted in the array in order to obtain an omni-directional sensor system. It will also be understood that in other systems or applications, as few as a single sensor can be used. Other force or acceleration sensors also can be used, including an accelerometer or system of accelerometers, piezoelectric shock sensors, electrolytic tilt sensors and other acceleration sensors. In addition, it would also be possible to provide a mass suspended from a cantilevered beam that is gauged such as with a strain gauge and use the strain gauge to sense a jarring event. In short, any sensor that can be made to sense acceleration is a possible sensor for stopping the firing sequence of the firearm in event of a jarring or unauthorized force application or unnecessary rapid acceleration. As the firearm is subjected to a jarring event or accelerated above a certain sensor limit or threshold, a sensor signal is generated to indicate a fault condition, in response to which the control system will block the firing sequence and prohibit the firearm from firing.
The sensor system further generally will be capable of measuring or sensing the orientation of the firearm along two or more axes of angle measurement relative to the earth. The first axis of measurement generally is inclination or elevation. The second axis of angle measurement generally measures rotation of the firearm about its bore. The sensor system for obtaining these orientation measurements generally includes an orientation sensor, such as a three-axis magnetometer. However, any sensor or array of sensors that can determine the gun""s orientation with respect to a reference or threshold is capable of being used, including, for example, tilt or tip-over switches, inclinometers, accelerometers, and gyros or other types of sensors that can be used to sense or monitor firearm orientation can be used in the present invention. The sensors monitor and generate sensor signal(s) indicating the orientation of the firearm with respect to the predetermined axes, which sensor signal is communicated to the control system. The control system will process the sensor signal(s) to determine if the firearm is in an acceptable firing orientation. If the orientation is determined to be improper or unacceptable, the control system will issue an interrupt signal that will stop the firing sequence if the trigger is pulled.
Though in a preferred embodiment a firearm is kept from firing if it has experienced a jar situation and/or is in an improper orientation, the system does not need to do both. It is possible that a system of sensors could be used to sense only acceleration or a jar event, or the movement of the firearm to an undesired orientation alone to keep the firearm from firing.
The control system of the firearm sensor system further generally will communicate with a fire control, trigger system and/or a safety system for the firearm. The control system can include a separate control system mounted within the frame, stock, receiver or other portion of the firearm, or can be included as part of a firearm control system of an electronic firearm such as disclosed in U.S. Pat. No. 5,755,056, the disclosure of which is incorporated herein by reference. The control system blocks or permits the firing sequence to proceed depending on a sensor output signal.
The halting of the firing sequence is accomplished in firearms that are electrically initiated by the control system issuing an interrupt signal to stop the transmission of a firing pulse to a round of electrically activated ammunition. The sensor system of the present invention also could be applied to a conventional percussion firearm as well, such as by controlling a solenoid-activated stop to hold a firing pin in a ready to fire position and block a percussion type fire control from imparting or releasing its energy to a round of percussion ammunition to initiate a firing sequence.
Various objects, features, and advantages of the present invention will become apparent to those skilled in the art upon a review of this specification when taken in conjunction with the accompanying drawings.